This invention relates to processing piezoelectric material.
Piezoelectric materials can generate electricity or a voltage differential when subjected to mechanical stress. Alternatively, applying a voltage across a piezoelectric material can cause converse piezoelectricity, that is, the piezoelectric material mechanically deforms when a voltage is applied. Converse piezoelectricity can cause bending forces in the piezoelectric material that are extremely high. Both of these properties, generating electricity and converse piezoelectricity, are harnessed for use in electrical and mechanical devices, such as transducers, e.g., actuators and sensors. Multiple transducers, including a combination of actuators and sensors, can be combined together in a microelectromechanical system (MEMS).
A MEMS typically has mechanical structures formed in a semiconductor substrate using conventional semiconductor processing techniques. A MEMS can include a single structure or multiple structures. MEMS have an electrical component, where an electrical signal activates each or is produced by actuation of each structure in the MEMS.
One implementation of a MEMS includes a body having chambers formed in the body and a piezoelectric actuator formed on an exterior surface of the body. The piezoelectric actuator has a layer of piezoelectric material, such as a ceramic, and elements for transmitting a voltage, such as electrodes. The electrodes of the piezoelectric actuator can either apply a voltage across the piezoelectric material or transmit a voltage that is produced when the piezoelectric material is deformed.